Definition
A satellite-based radio navigation system that provides aircraft with highly accurate position, velocity, and time information anywhere in the world, in any weather, 24 hours a day. The aircraft's GPS receiver determines its location by measuring the time it takes for signals to arrive from multiple satellites in known orbits, and triangulating from those measurements.
Plain English
A navigation system that uses signals from satellites in space to tell the aircraft exactly where it is, how fast it is moving, and what time it is. The receiver in the aircraft listens to several satellites at once and works out its position from the timing of those signals.
Context Anchor
Pilots encounter GPS on panel displays, handheld receivers, flight-planning tools, and route information used for navigation.
Derivation
The name describes what the system does: it positions you globally — anywhere on Earth — using a coordinated system of satellites. Originally a U.S. military system (NAVSTAR GPS) opened up for civilian use, the term is now used generically for satellite navigation in everyday aviation language.
Why Pilots Care
It supplies continuous, accurate navigation data that supports direct routing, instrument approaches, and reduced pilot workload in all weather conditions.
Intuition Check
GPS is not just the moving map screen in the cockpit. The screen displays information from the GPS system, but the system itself is the satellite signals and receiver that determine position.
Example Sentence 1
The pilot selected the destination airport on the GPS and the unit displayed the direct course and distance.
Example Sentence 2
When the primary navigation aid failed, the crew switched to GPS for position updates.